<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script type="text/javascript" src="./js/ctx.js"></script>
</head>
<body>
<div id="cesiumContainer">
</div>
<div id="toolbar">
    <table><tbody>
    <tr>
        <td>Luminance at Zenith</td>
        <td>
            <input type="range" min="0.0" max="2.0" step="0.01" data-bind="value: luminanceAtZenith, valueUpdate: 'input'">
            <input type="text" size="4" data-bind="value: luminanceAtZenith">
        </td>
    </tr>
    </tbody></table>
</div>


<script>
    var initCesium = new InitCesium();

    var viewer = initCesium.initViewer('cesiumContainer');

    var environmentMapURL = '../data/EnvironmentMap/kiara_6_afternoon_2k_ibl.ktx';
    var modelURL = '../data/models/Pawns/Pawns.glb';

    // This environment map was processed using Google's Filament project. To process your own:
    // 1 - Download the Filament release (https://github.com/google/filament/releases).
    // 2 - Run `cmgen --type=ktx --deploy=/path/to/output /path/to/image.hdr`. Other formats are also supported. Run `cmgen --help` for all options.
    // 3 - Take the generated coefficients and the KTX file and load them in CesiumJS as shown below.

    var L00  = new Cesium.Cartesian3( 0.170455150831422,  0.163151083190219,  0.196966760289763);
    var L1_1 = new Cesium.Cartesian3(-0.066550267689383, -0.022088055746048,  0.078835009246127);
    var L10  = new Cesium.Cartesian3( 0.038364097478591,  0.045714300098753,  0.063498904606215);
    var L11  = new Cesium.Cartesian3(-0.014365363312810, -0.026490613715151, -0.050189404066020);
    var L2_2 = new Cesium.Cartesian3(-0.051532786917890, -0.050777795729986, -0.056449044453032);
    var L2_1 = new Cesium.Cartesian3( 0.043454596136534,  0.046672590104157,  0.057530107646610);
    var L20  = new Cesium.Cartesian3(-0.001640466274110,  0.001286638231156,  0.007228908989616);
    var L21  = new Cesium.Cartesian3(-0.042260855700641, -0.046394335094707, -0.057562936365585);
    var L22  = new Cesium.Cartesian3(-0.004953478914091, -0.000479681664876,  0.008508150106928);
    var coefficients = [L00, L1_1, L10, L11, L2_2, L2_1, L20, L21, L22];

    var height = 0.0;
    var hpr = new Cesium.HeadingPitchRoll(0.0, 0.0, 0.0);
    var origin = Cesium.Cartesian3.fromDegrees(-123.0744619, 44.0503706, height);
    var modelMatrix = Cesium.Transforms.headingPitchRollToFixedFrame(origin, hpr);

    var model = viewer.scene.primitives.add(Cesium.Model.fromGltf({
        url : modelURL,
        modelMatrix : modelMatrix,
        minimumPixelSize : 128
    }));

    model.readyPromise.then(function(model) {
        var camera = viewer.camera;

        // Zoom to model
        var controller = viewer.scene.screenSpaceCameraController;
        var r = 2.0 * Math.max(model.boundingSphere.radius, camera.frustum.near);
        controller.minimumZoomDistance = r * 0.5;

        var center = Cesium.Matrix4.multiplyByPoint(model.modelMatrix, model.boundingSphere.center, new Cesium.Cartesian3());
        var heading = Cesium.Math.toRadians(230.0);
        var pitch = Cesium.Math.toRadians(-20.0);
        camera.lookAt(center, new Cesium.HeadingPitchRange(heading, pitch, r * 2.0));
        camera.lookAtTransform(Cesium.Matrix4.IDENTITY);

        model.sphericalHarmonicCoefficients = coefficients;
        model.specularEnvironmentMaps = environmentMapURL;

        // The viewModel tracks the state of our mini application.
        var viewModel = {
            luminanceAtZenith : model.luminanceAtZenith
        };
        // Convert the viewModel members into knockout observables.
        Cesium.knockout.track(viewModel);

        // Bind the viewModel to the DOM elements of the UI that call for it.
        var toolbar = document.getElementById('toolbar');
        Cesium.knockout.applyBindings(viewModel, toolbar);

        function subscribeParameter(name) {
            Cesium.knockout.getObservable(viewModel, name).subscribe(
                    function(newValue) {
                        model[name] = newValue;
                    }
            );
        }

        subscribeParameter('luminanceAtZenith');

        Sandcastle.addToggleButton('Use procedural image', false, function(checked) {
            if (!checked) {
                model.sphericalHarmonicCoefficients = coefficients;
                model.specularEnvironmentMaps = environmentMapURL;
            } else {
                model.sphericalHarmonicCoefficients = undefined;
                model.specularEnvironmentMaps = undefined;
            }
        });
    }).otherwise(function(error){
        window.alert(error);
    });

</script>
</body>
</html>